Overheated 2.5L Mazda

I have a Mazda with 2.5L V6 engine.

I overheated the car so badly, it stalled as I was pulling into the
parking space. Upon examination, I found out that it needed a gallon of
radiator fluid and that it was leaking really badly from the water pump
area. I also have a small leak from the radiator but nothing so bad,
needed maybe a quart every two days. I don't think it's the cause of
the overheating. Also, my temp. gauge does not work so I had no idea
the temp. was that high.

Question, how much damage have I done?

I haven't driven it since then of course. I filled it up with water,
run it for 5 minutes and did not see any coolant in oil or vice-versa
nor did I hear any strange noises like before. (Worn out water pump? Or
something inside the engine?)
Tomorrow I should know if it smokes white, which is a sure sign of head
gasket failure, which is my real concern.

SQ wrote:
> I have a Mazda with 2.5L V6 engine.
>
> I overheated the car so badly, it stalled as I was pulling into the
> parking space. Upon examination, I found out that it needed a gallon of
> radiator fluid and that it was leaking really badly from the water pump
> area. I also have a small leak from the radiator but nothing so bad,
> needed maybe a quart every two days. I don't think it's the cause of
> the overheating. Also, my temp. gauge does not work so I had no idea
> the temp. was that high.
>
> Question, how much damage have I done?
>
> I haven't driven it since then of course. I filled it up with water,
> run it for 5 minutes and did not see any coolant in oil or vice-versa
> nor did I hear any strange noises like before. (Worn out water pump? Or
> something inside the engine?)
> Tomorrow I should know if it smokes white, which is a sure sign of head
> gasket failure, which is my real concern.

You may get lucky.

A car my parents had blew a radiator hose and overheated. After
refilling the radiator we had coolent coming out the tailpipe.

Get the water pump fixed !

get it fixed then go from their?

if you knew it was leaking you should have fixed it then ---know it
may cost you mega bucks if it's major motor problems

thanks for keeping the mechanics busy

"SQ" > writes:

>I have a Mazda with 2.5L V6 engine.

>I overheated the car so badly, it stalled as I was pulling into the
>parking space. Upon examination, I found out that it needed a gallon of
>radiator fluid and that it was leaking really badly from the water pump
>area. I also have a small leak from the radiator but nothing so bad,
>needed maybe a quart every two days. I don't think it's the cause of
>the overheating. Also, my temp. gauge does not work so I had no idea
>the temp. was that high.

>Question, how much damage have I done?

Aluminum head(s)? Good luck. Aluminum block? Start praying.

Hopefully the motor is not seized. Try turning it over by hand as a
preliminary assessment. If is not seized, you can run it for just long
enough to assess its condition even with the bad water pump, once it has been
sitting and is cold. While it is running, look for steam out the tailpipe,
bubbles in the radiator, oil in the radiator, milky oil, external oil leaks
from HG area, etc. After running it, shut it down and let it sit. Remove
the spark plugs and check for water in the cylinders. If you don't detect
any problems up to this point, it may be worth repairing, but you still may
have a gasket failure in your future.

By the way, it is not a good idea to run a car with a leaking cooling system,
even if the leak is minor. If it is leaking externally, it is not cooling
effectively, because the coolant's density is decreased as it wants to boil.

SQ wrote:

> I also have a small leak from the radiator but nothing so bad,
> needed maybe a quart every two days. I don't think it's the cause of
> the overheating.

Here's a problem. You don't think a quart every two days could cause
overheating?

> Also, my temp. gauge does not work so I had no idea
> the temp. was that high.

Here's a problem. You have been driving with an inoperative temp
gauge?

> I overheated the car so badly, it stalled as I was pulling into the
> parking space. Upon examination, I found out that it needed a gallon of
> radiator fluid and that it was leaking really badly from the water pump
> area.

Here's a problem. At this point metal transfer has probably occured
between the pistons and cylinder walls, not to mention cylinder warpage
and extreme heat stress to other vital components such as crank,
bearings, head mating surfaces, and valve guides.

> Tomorrow I should know if it smokes white, which is a sure sign of head
> gasket failure, which is my real concern.

The entire block could be esentially wasted at this point and the head
gaskets could still hold coolant. Head gaskets don't cause an engine
to seize!

If it starts and runs and doesn't belch oil out the tail pipe and into
the air cleaner housing, then you may have a chance at salvaging the
engine. If this is the case, you may want to consider the following:
Change the oil and filter, keep a sample of the old oil, run the engine
again for about 15 minutes (keeping radiator topped off) then stop
engine and drain a sample of the "clean oil" and send both samples to
be tested. If the "clean" sample shows a extrordinary amount of
aluminum, lead, tin, and steel then you will probably want to junk the
engine. OTOH, if both samples are relatively metal free given their
respective time spent in the engine, then you are *probably* OK and
should proceed with the waterpump and radiator replacement. And then
fix the temp gauge problem. It's probably just a loose wire or broken
terminal at the sender.

Toyota MDT in MO

Oil sample. Good idea. I will do just that.

I put water in the engine, started it, did not hear any noises nor did
I see any white smoke come out of the tail pipe. I still have hope I
haven't done damage to it.

Temp. sensor, I replaced it twice - and it had it explode on me
twice as soon as the vehicle is turned on. Explode literally, where it
is torn in half. I don't know what can cause this. Some electrical
issue, but how to troubleshoot?

SQ wrote:
> Oil sample. Good idea. I will do just that.

> Temp. sensor, I replaced it twice - and it had it explode on me
> twice as soon as the vehicle is turned on. Explode literally, where it
> is torn in half. I don't know what can cause this. Some electrical
> issue, but how to troubleshoot?

If you can light a standard test light by touching it to the sending
unit connector terminal with the key on, then there is a problem in the
instrument cluster or temp gauge. I'm just guessing here that the
sender thermister is seeing a full 12 volts and burning up. There is
measurable voltage in the sender circuit if you use a high impedence
voltmeter, but it of extremely low current capacity. Perhaps full B+
power is being shorted to that wire; again, think instrument cluster

Toyota MDT in MO